Process for the production of solid ammonium salts



June 12, 1934.

PROCESS FOR THE PRODUCTION OF SOLID AMMONIUM SALTS G. FAUSER 1,962,185

Filed May `8, 1928 I lill I Q I llllllHlll R y Et Il* D: E@ S w Qs lllll\ mm mi s g mm3; vu

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; nl E Jcren/ 627/7 VQ/or Giacomo U55? UNITED STATES PATENT OFFICEPROCESS FOR THE PRODUCTION OF SOLID AMMONIUM SALTS Giacomo Fauser,Novara, Italy, assignor to Montecatini, Societa Generale Per LIndustriaMincraria Ed Agricola, Milan, Italy, a jointstock company of ItalyApplication May 8, 1928, Serial No. 276,181 In Italy June 14, 1927 4Claims. (Cl. 23-50) The process at present in use for the productionrectication column E, the steam is condensed of ammonium salts is thatof bubbling the gaseous and forms an ammonia solution` l'Ihis solutionammonia through an acid and of separating from falls in saidrectification column over a series the mother lyes the salt crystalsthat have formed. of trays E' being in direct heat conductive con- 5This process is very complicated inasmuch as it tact with the very hotgases arriving from the 65 involves the employment of ejectors in orderto reaction chamber. Said solution then gives off raise the salt thathas deposited at the bottom of its gaseous ammonia whilst the `remainingwater the saturator; of centrifugal machines or filters is collected inthe bottom of said rectification in order to separate the mother lyes;and of dryers column and is discharged through automatic in order toremove the last traces of ,moisture valve G connected to the lowerportion of said 65 Such apparatus, besides absorbing a considerablerectification column. amount of motive power, are liable to rapid wearWhere gaseous ammonia is supplied by a plant owing to their being alwaysin contact with more for the production of synthetic ammonia, theamorless acid solutions, and require a considerable monia is delivereddirect into the reaction chamexpense for upkeep. y ber through the cockH.

The subject matter of the `present invention 'Ihe acid supply regulatorI serves to effect regis an improved process by which perfectly dryulation of the quantity of the acid delivered with ammonium salts aredirectly obtained in a solid respect to the quantity of ammoniadelivered. and neutral condition without using any cen- When thepressure inside of the reaction chamtrifugal machines or any dryers,hence in a much ber tends to increase owing to the presence of an 75cheaper way. ammonia excess, the bell I rises and thereby.

'I'he process according to the invention essen-l opens the valve L, theacid supply being thus intially distinguishes itself from thoseheretofore creased. When on thel contrary the ammonia de` employed bythe fact that instead of bubbling the livery decreases, the pressureinside the reaction gaseous ammonia through the acid, the acidis chamberalso decreases, whereupon a closing 50 sprayed and atomized in anammonia atmosof the valve L by the bell I ensues; in this manner phere.y the equilibrium between the acid supply and the The apparatus forcarrying the process into ammonia supply is automatically restored.eiect is illustrated in the accompanying draw- Where the availableammonia is in the form of 3 ing; it should be understood, however, thatthe aqueous solution, the heat generated by the re- 35 invention is byno means coniined to the details action can be utilized to distill theammonia. In

indicated on the drawing, such a case at the beginning, in order tostart the The apparatus Afsseiltlally COmDIjiScS a reaapparatus, it isnecessary to warm up the bottom tlOn Chamber A cnamlng ammOnla 1D gSeOuSportion of the rectification column by circulating Condition; the acidis SPlaYed into this Chamber steam controlled by valve N through thecoil M, 9th

by means 0f a Sutab1e`afl0mizer B Positioned the condensed Water beingautomatically disnear the ceiling thereof.. 'Ifhe degree ofconcencharged by the valve Q tration of the acid should beso selectedthat the The ammonia Solution delivered into the rect heat develope@ byth? reacPl-n of the amd Wlth cation column through the cock P ispreheated 40 that ammo?? lsyment Et evaporate au of the in the preheaterQ at the expense of the heat of Wapg; falll flgtheepddion of ammoniumthe water from the lower portion of said rectili- Sulfate it isSufficient to use Sulphuric acid haw cat1on column and is then deliveredinto the recting a concentration of B' The hat de fication column at thetop ofthe latter.

veloped by the reaction is such that the temper- HaVlng W partlculallydescllbed and asce" ature rises at once to C. and 9,11 of the watertamed the nature of my Said invention and in present in the acid isthereby evaporatedwhilst what manner the Same iS t0 be performed, Idethe salt formed collects on the bottom of the Clare that WhatIClaimiSIchamber and is continually,removed-therefrom 1. The process of formingsolid ammonium f 50 by a screw conveyor C. salts which comprisescontinuously atomizing a 105 In order to remove the vapor thus formed,the liquid acid into a chamber containing ammonia mixture of ammonia andsteam, present in the gas under such conditions that solid salts areob-` chamber A, is continually circulated through a tained throughevaporation of water introduced rectification column E by a fan D. Ontraverswith the acid, continuously removing excess gas 55 ing a coolingcoil F disposed at the top of the from the chamber, removing moisturefrom said no gas and recirculating the so puried gas through the chambertogether with fresh ammonia gas.

2. The continuous process for directly producing solid ammonium salts indry form, which consists in spraying and atomizing acid intended to becombined with ammonia from the upper portion of -a reaction chamberdownward in a gravitational direction through an atmosphere of gaseousammonia fed into said chamber simultaneously controlling the supply ofacid by means of the gas pressure in the chamber, and continuouslycollecting and discharging the resulting solid salts deposited in thebottom ofr said reaction chamber.

3. The continuous process fory directly producing solid ammonium saltsin dry form from an aqueous solution of ammonia, consisting in sprayingand atomizing a concentrated acid into an atmosphere of ammonia gaswithin a reaction chamber, the amount of ammonia being greater than thatrequired for the occurring reaction, passing the ammonia and steammixture resulting from said reaction to and through a rectificationcolumn, utilizing part of the heat generated by this reaction to distillwithin said rectification column the excess ammonia from said reactionchamber, whereby to condense the water and recuperate the gaseousammonia present in said ammonia and steam mixture, and continuouslycollecting and discharging the resulting solid salts deposited at thebottom of the reaction chamber.

4. The continuous process for directly producing solid ammonium salts ina dry condition, consisting in spraying and atomizing a concentratedacid within a reaction chamber, the degree of concentration of whichacid is such that the heat developed by the reaction of the acid withthe ammonia is suicient to evaporate the water present in the acid, intoan atmosphere of ammonia gas within said reaction chamber, passing theammo nia and steam mixture resulting from this evaporation to andthrough a rectification column containing a cooling coil in order tocondense the steam and recuperate the gaseous ammonia present in saidammonia and steam mixture, continuously collecting and discharging theresulting solid salts deposited at the bottom of the chamber Where thereaction takes place, and returning to the cycle the gaseous ammoniawhich is recuperated from the rectification column.

GIACOMO FAUSER.

